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Finding the Fourth Proportional to 660.80, 990.35 and 313.61

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Solution

The fourth proportional to 660.80, 990.35 and 313.61 is: 470.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.80 : 990.35 = 313.61 : x
  2. Step 2: Convert to fraction form
    660.80/990.35 = 313.61/x
  3. Step 3: Cross multiply
    660.80x = 990.35 × 313.61
  4. Step 4: Simplify right side
    660.80x = 310,577.14
  5. Step 5: Solve for x
    x = 310,577.14/660.80
  6. Step 6: Final answer
    x = 470.01

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.